Rotary piston internal combustion engine, especially circular piston internal combustion engine



Feb. 20, 1968 H ABERMETH 3,369,740

ROTARY PISTON INTERNAL COMBUSTION ENGINE, ESPECIALLY CIRCULAR PISTONINTERNAL COMBUSTION ENGINE Filed May 1, 1967 Fig.1

Fig. 2

United States Patent Claims. c1.230-145 ABSTRACT OF THE DISCLOSURE Thepresent invention relates to a rotary piston internal combustion engineof the type which has an exhaust gas collecting chamber between a sidewall of the engine housing and the piston journalled in bearing means insaid side wall, while gear means are respectively arranged near saidchamber means and are respectively connected to said side wall and saidpiston for kinematically controlling the piston.

The invention is characterized primarily in that the said bearing meansand gear means are sealed with regard to said exhaust gas collectingchamber means by a three sectional labyrinth seal with the first sectionthereof connected to said side wall, the second section thereofconnected to said piston, and with the third section arranged betweensaid first and second sections, said first and second sections havingcircular teeth respectively cooperating with oppositely extending teethof said third section.

The present invention relates to a rotary piston internal combustionengine, especially circular piston internal combustion engine in whichthe piston profile is determined by a trochoid, preferably epitrochoid,while accordingly,

the housing propile follows the outer enveloping curve of the trochoid.The present invention is particularly directed to an engine of the abovementioned type, in which for purposes of realizing the four-stroke cyclemethod, a piston is employed, the circumference of which has a number ofaxis-near zones or lobes divisible by 2, said piston between twosuccessive axis-near zones being provided with an inlet-control openingand an outlet-control opening. The inlet and outlet control openings arerespectively connected through passages or the like in the piston withinlet and outlet openings provided in the end-faces of the piston anddirectly or indirectly leading into a sealed collecting chamber of thehousing, the seal of which is effected in a contact-free manner througha labyrinth. Such engine is disclosed e.g. in assignees patentapplication filed Apr. 17, 1967, under Ser. No. 631,459 and based onGerman application Ser. No. K 59,043 filed Apr. 20, 1966.

With a rotary piston internal combustion engine of the above mentionedtype, the collecting chambers may have connected thereto simple conduitmeans leading toward the outside. However, the said collecting chambersmust be sealed with regard to the transmissions and bearings. This sealcauses considerable difiiculties because the sealed elements or partshave to move relative to each other with an eccentricity.

It is, therefore, an object of the present invention to provide a rotarypiston internal combustion engine, especially circular piston internalcombustion engine, with means which will properly seal the transmissionsand bearing portions relative to the gas collecting chambers.

It is another object of this invention to provide an engine as set forthin the preceding paragraph in which the seal will be simple inconstruction and highly effective.

These and other objects and advantages of the in- 3,369,740 PatentedFeb. 20, 1968 vention will appear more clearly in the followingspecification in connection with the accompanying drawing, in which-FIG. 1 diagrammatically illustrates a section through a portion of acircular piston internal combustion engine provided with a sealaccording to the present invention.

FIG. 2 illustrates on a somewhat larger scale than FIG. 1 the way inwhich the labyrinth seal according to FIG. 1 operates.

The labyrinth seal, according to the present invention, is characterizedprimarily in that it comprises three sec tions of which one section isconnected to the piston, while a second section is connected to theeccentric shaft, and a third section is connected to the sidewall of thehousing, the second or intermediate section with labyrinth forming teethengaging correspondingly formed counterteeth of the two other sections.

Referring now to the drawings in detail, FIG. 1 shows a circular pistoninternal combustion engine with a piston 1, the profile of which isdetermined by an epitrochoid, while the inner contour of the profile ofthe housing follows the outer enveloping curve of they epitrochoid. Thepiston 1 is journalled on an eccentric shaft 3. For kinematicallycontrolling the piston 1, there is provided a pinion 4 connected to thepiston 1 and cooperating with a hollow gear 5. The bearing for theeccentric shaft in the housing sidewall 6 is designated with thereference numeral 7. The bearing 7 and the transmission forkinematically controlling the piston are sparated from the exhaust gascontrolling chamber -8 by a labyrinth seal.

As will be seen from the drawing, this labyrinth seal comprises twosections of which the section 9 is connected to the piston 1, while thesection 10 is connected to the eccentric shaft 3, and the section 11 isconnected to the sidewall 6 of the housing 2. With this arrangement ofthe labyrinth sections, the labyrinth teeth 12 form annular members orrings which can easily be produced as bodies of revolution on a lathe orautomat. According to the embodiment shown in FIG. 1, the labyrinth,section 11 forms a single integral piece with the hollow gear 5. Forpurposes of improving the sealing effected, the labyrinth sections 9 and10 are provided with splash rings 13, 14. Moreover, the cylindrical seatof the labyrinth section 9 is provided with a seal 15.

The operation of the labyrinth seal is best seen from FIG. 2, whichshows the labyrinth seal on a somewhat larger scale than FIG. 1.However, in contrast to FIG. 1, the labyrinth section 11' and the hollowgear 5 consist of two pieces. Furthermore, a splash ring 16 isinterposed between the hollow gear 5 and the labyrinth section 11.

As will be evident from the above, the labyrinth seal, according to thepresent invention, permits an easy bridging of the eccentricity of themovable parts relative to the stationary parts. Moreover, all sectionsof the labyrinth seal are of a simple design so that they can easily beproduced on corresponding machine tools.

It is, of course, to be understood that the present invention is, by nomeans, limited to the illustrated discharge side of a circular pistoninternal combustion engine, but can also be provided with all of thoseadvantages on the inlet side of the engine. Furthermore, the inventionis not limited to a rotary piston internal combustion engine but canalso be employed for circular piston internal combustion engines.

What I claim is:

1. A rotary piston internal combustion engine, especially circularinternal combustion engine, with a piston profile determined by atrochoid and with a housing having an inner peripheral profile followingthe enveloping curve for said trochoid, which includes: side wall meansforming part of said housing, bearing means located in said side 3 wallmeans, an eccentric shaft rotatably journalled in said bearing means andsupporting said piston, control means respectively connected to saidside wall means and said piston for kinematically controlling themovement of said piston, exhaust gas collecting chamber means arrangedbe tween-said side wall means and said piston, and labyrinth sealingmeans interposed between said bearing means and said control means onone hand and said chamber means on'the other hand for sealing saidbearing means and said control means with regard to said chamber means,said labyrinth sealing means comprising a first section connected tosaid side wall means and provided with circular tooth means facingtoward said piston, said labyrinth sealing means comprising a secondsection connected to said piston and provided with circular tooth meansfacing toward the tooth means of said first section, said labyrinthsealing means also comprising a third section connected to saideccentric shaft and having oppositely directed circular tooth meansinterposed between said first and second sections and in respectivesealing arrangement with the tooth means thereof.

2. An engine-according to claim 1, in which each of said labyrinthsealing sections has a plurality of radially spaced teeth.

3. An engine according to claim 2, in which the circular teeth on oneside of said third section are radially offset with regard to thecircular teeth on the opposite side of said third section.

4. An engine according to claim 1, in which said control means include agear ring with inner teeth forming an integral part with said firstsection and also include gear means connected to said piston and meshingwith 'said gear ring.

5. An engine according to claim 1, in which said control means include agear ring interposed between and firmly connected to said side wallmeans and said first section and also include gear means connected tosaid piston and meshing with the teeth of said gear ring.

References Cited 5 DONLEY J. STOCKING, Primary Examiner.

WILBUR J. GOODLIN, Examiner.

